Process of treating coffee.



No. 736,346. I PATENTED AUG. 18, 1903.

w. E. BAKER.

PROCESS OF TREATING COFFEE.

. APPLICATION FILED APR. 3, 1903.

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I f No. 736,346.

purification ofthe cut coffee.

UNITED I STATEs Patented August 18, 1903.

ATENT macs.

WILLIAM BAKER, OF MINNEAPOLIS, MINNESOTA.

PsocEss OF TREATING COFFEE.

SPECIFICATION forming part of Letters Patent No.73 6,3416, dated August18, 1903.

Application filed April 3, 1903- Serial No. 150,890- (No specimens.)

resident of Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements inProcesses of Treating Cofiee, of which the following is a specification.

Myinvention is designed for the production of an improved article ofmanufacture consisting of finely-cut roasted coffee having granules ofuniform size and having the dust, chaff, and other impurities, includinga portion of the tannic acid, removed therefrom; and the inventionresides in a novel process of treating the cofieeand in the improvedproduct obtained as a result thereof.

This invention is an improvement on the subject-matter described in myPatent No. 726,8l2, dated April 28, 1903, for an improve ment inprocesses of. treating coffee. In the patent referred to the product isthe result of crushing the coffee by means of smoothsurfacedflattening-rolls which free the silver skins and of separating saidskins from the broken bodies of the beans.

In the present invention the improved coffee is a graded andhighly-purified product of sharply-dressed mechanism, the action ofwhich is to out rather than to crush or grind, which leaves theparticles in a condition analogous to that of sharps or middlings ofgrainviz., uncompressed, and therefore more read ily permeable to hotwater. I have found that roasting renders the body proper of thecofiee-bean exceedingly brittle, while the embedded silver skins remainrelatively flexible. These conditions facilitate the subsequent As aresult of my improved process the final product is superior in manyrespects to ordinary ground or granulated coifee-that is to say, itpresents a much better appearance, in that the angular particles are ofregular size and do not disclose the presence of dust or flakes ofsilver skins therein. As these silver skins in the interior of the beancontain a large percentage of tannic acid,an important deleterionsmatter has been removed and the instead of crushing I obtain a productwhich will more quickly and with lesswaste of the granulated coffeeproduce a strong and aromatic beverage.

It is the purposeof my invention to produce a clean regularly-cutproduct which is uncompressed or only slightly compressed, and thereforequick to absorb water.

One form of apparatus by which my invention can be carried out isillustrated in the accompanying drawings, in which- Figure 1 is asectional elevation, and Fig. 2 is a perspective view,of a pair of thecutting rolls.

This apparatus consists of a casing A, having a chute 2 at its upper endand a pair of sharply-dressed or cutting rolls B and C below said chute.The coffee-beans after being roasted in the ordinary manner, whereby thebody of the bean is rendered brittle, while the embedded silver skinremains relatively flexible, is fed through said chute between saidrolls. These rolls are revolved by any suitable means (not shown) in thedirection indicated by the arrows and at different surface speeds andcut the coffee-beans into coarse granules, thus freeing the silverskins. Beneath the cutting-rolls B and O is located a reciprocating orshaking screen 5, the same consisting of a frame having a covering 6, ofbolting-cloth, wirenetting, or other reticulated material. The frame ofthe screen 5is pivoted at its opposite ends to links 7 and 8, which arethemselves pivoted to the frame of the casing A at their lower ends.These links constitute supports for the screen 5, and the latter isadapted to be reciprocated. by means of a pitman-rod 9, connected withthe link '7 and operated in any suitable manner, Beneath the screen 5 isa closed chamber 10, formed by a bottom piecell and end piece 12, andflexible webs 13 and 14, connected, respectively, with the frame of thescreen 5 at opposite ends and with the end piece 12 and side wall of thecasing A. Into the chamber 10 leads an air-inlet pipe 15, through whicha blast of air is adapted to be forced, and from the casing A, above thescreen 5, leads an exhaust-pipe 16. The screen 5 is slightly inclinedbelow the cutting-rolls, so that the particles of cofiee when deliveredthereon may be caused to pass from one end thereof, as

screen, which is constantly being shaken or agitated by the meansdescribed, the cut coffee is subjected to a blast of air entering thechamber beneath the screen 5 through the pipe 15 and discharging throughthe exhaustpipe 16. This current or blast of air carries oif with it thelight particles of matter contained in the coffee, consisting of thedust and the chaff, which latter is produced by the silver skin from theinside of the coffeebean. As the operation continues the particles ofcoifee are discharged from the delivery end of the screen 5 into thechute or hopper 21 and are then caused topass be tween a second pair ofsharply-dressed or cutting rolls D and E, which have a larger num ber ofcutting edges 21 than the first pair. In other respects the second pairof rolls is similar in construction and operation to the first pair ofrolls B and O. By the latter rolls the coffee is reduced to a morefinely out 0011- dition, and from the same it is delivered onto theshaking-screen 22, which is similar in all respects to the screen 5heretofore referred to. The screen 22 has beneath it a chamber 23,similar to the chamber 10 and connected with the screen 22 in a similarmanner to that above described.

Leading into the chamber 23 is an air-inlet pipe 24:, and leadingfromthe casing A, above the screen 22, is an exhaust-pipe 25. On thescreen 22 the coffee is subjected to the action of a second blast ofair, which enters the chamber 23 beneath said screen through the pipe24: and discharges from the point above the screen through theexhaust-pipe 25. Any chaff, dust, or other light finely-dividedimpurities which escape the action of the blast of air passing throughthe screen 5 are removed by the blast of air to which the coffee issubjected on the screen 22. The screen 22 is inclined and discharges thecoffee therefrom into the chute or hopper 26, whence it may be deliveredfrom the machine to any suitable point. The rolls D and E are locatednear the parts 19 and 20 of a transverse diaphragm, which prevents thepassage of the air-current from the inlet-pipe 24 through theexhaust-pipe 16. Of course, if desired, the product delivered from themachine through the discharge-chute may be further cut.

I have shown and described two sets of cutting-rolls and means forsubjecting the cut coffee to the action of a blast of air; but it isobvious that I may increase or decrease the number of these sets ofinstrumentalities as may be found necessary or expedient.

Having described my invention, what I claim as new, and desire toprotect by Letters Patent, is

1. The process of preparing coffee for use, which consists in removingthe outer skin, roasting the coffee, whereby the berry is renderedbrittle, while the embedded silver skins remain flexible, cutting theroasted berry,

and releasing the skins, and finally separating the skins from the cutgranules by means of an air-current.

2. The process for treating coffee, which consists essentiallyin firstroasting the coffeebean, whereby the body of the bean is renderedbrittle, while the embedded silver skin remains relatively flexible,then cutting the roasted bean into relatively uncompressed and uniformgranules and freeing the silver skins, and finally separating said skinsfrom the cut body of the bean.

3. As a new article of manufacture, the roasted body of the coffee-bean,cut into granules and freed from the embedded silver skins.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

l/VILLIAM E. BAKER.

Witnesses:

, E. M. BOESEL,

F. G. BRADBURY.

